输入法框架imf错误码信息相关资料补充

Signed-off-by: NHollokin <taoyuxin2@huawei.com>

zh-cn/application-dev/reference/apis/js-apis-inputmethod.md

@@ -635,8 +635,7 @@ InputMethodController.hideSoftKeyboard((err) => {
 })
 ```
 
-
-### hideSoftKeyboard<sup>9+</sup> ###
+### hideSoftKeyboard<sup>9+</sup>
 
 hideSoftKeyboard(): Promise&lt;void&gt;
 
@@ -664,7 +663,7 @@ InputMethodController.hideSoftKeyboard().then(async (err) => {
 
 下列API示例中都需使用[getSetting](#inputmethodgetsetting)回调获取到InputMethodSetting实例，再通过此实例调用对应方法。
 
-### on('imeChange')<a name="imeChange"></a>
+### on('imeChange')<a name="imeChange"></a><sup>9+</sup>
 
 on(type: 'imeChange', callback: (inputMethodProperty: InputMethodProperty, inputMethodSubtype: InputMethodSubtype) => void): void
 

zh-cn/application-dev/reference/apis/js-apis-inputmethodengine.md

@@ -1674,17 +1674,21 @@ deleteBackward(length:number, callback: AsyncCallback<boolean>): void
 
 ```js
 var length = 1;
-InputClient.deleteBackward(length, (err, result) => {
-    if (err) {
-        console.error('deleteBackward err: ' + JSON.stringify(err));
-        return;
-    }
-    if (result) {
-        console.info('Success to deleteBackward.(callback) ');
-    } else {
-        console.error('Failed to deleteBackward.(callback) ');
-    }
-});
+try {
+    InputClient.deleteBackward(length, (err, result) => {
+        if (err) {
+            console.error('deleteBackward err: ' + JSON.stringify(err));
+            return;
+        }
+        if (result) {
+            console.info('Success to deleteBackward.(callback) ');
+        } else {
+            console.error('Failed to deleteBackward.(callback) ');
+        }
+    });
+} catch (err) {
+    console.error('deleteBackward err: ' + JSON.stringify(err));
+}
 ```
 
 ### deleteBackward<sup>9+</sup>